What it with the licking.

I am a pet owner, but not one of those who really delves into the psychology of them. Our cat is licking the dogs face. She even put her front paws on there so she could hold on and do it.
Cats don't lick too often, but does anyone know why she would do this with the dog?

We had the dog first, but he was outside more until the weather got cooler. She is also the younger pet. It is sad for me that she will try and play with mister lonely all the time (he wants 24/7 attention) and he rebuffs her by barking or leaving when she tries to play with him.